摘要：
描述 Given a string, you need to reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order 阅读全文
摘要：
描述 Given an index k, return the kth row of the Pascal's triangle. For example, given k = 3, Return [1,3,3,1]. 分析 先构造了一个杨辉三角，然后返回这个杨辉三角的最后一组值，没超时就万事大吉了 阅读全文
摘要：
描述 Given numRows, generate the first numRows of Pascal's triangle. For example, given numRows = 5, Return [ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1 阅读全文